Diabetic retinopathy (DR), one of the most serious complications of diabetes, has been associated with inflammatory processes. We have recently reported that interleukin (IL)-17A, a proinflammatory cytokine, is increased in the plasma of diabetic patients. Further investigation is required to clarify the role of IL-17A in DR. Ins2(Akita) (Akita) diabetic mice and high-glucose (HG)-treated primary Müller cells were used to mimic DR-like pathology. Diabetes induced retinal expression of IL-17A and IL-17 receptor A (IL-17RA) in Müller cells in contrast to ganglion cells. Further evidence demonstrated that retinal Müller cells cultured in vitro increased IL-17A and IL-17RA expression as well as IL-17A secretion in the HG condition. In both the HG-treated Müller cells and Akita mouse retina, the Act1/TRAF6/IKK/NF-κB signaling pathway was activated. IL-17A further enhanced inflammatory signaling activation, whereas Act1 knockdown or IKK inhibition blocked the downstream signaling activation by IL-17A. HG- and diabetes-induced Müller cell activation and dysfunction, as determined by increased glial fibrillary acidic protein, vascular endothelial growth factor and glutamate levels and decreased glutamine synthetase and excitatory amino acid transporter-1 expression, were exacerbated by IL-17A; however, they were alleviated by Act1 knockdown or IKK inhibition. In addition, IL-17A intravitreal injection aggravated diabetes-induced retinal vascular leukostasis, vascular leakage and ganglion cell apoptosis, whereas Act1 silencing or anti-IL-17A monoclonal antibody ameliorated the retinal vascular damage and neuronal cell apoptosis. These findings establish that IL-17A exacerbates DR-like pathology by the promotion of Müller cell functional impairment via Act1 signaling.
Animals ; Apoptosis ; Diabetic Retinopathy* ; Excitatory Amino Acids ; Ganglion Cysts ; Glial Fibrillary Acidic Protein ; Glutamate-Ammonia Ligase ; Glutamic Acid ; Humans ; In Vitro Techniques ; Interleukin-17* ; Interleukins ; Intravitreal Injections ; Leukostasis ; Mice ; Neurons ; Pathology ; Plasma ; Retina ; Retinaldehyde ; Vascular Endothelial Growth Factor A

OBJECTIVETo research the change of concentration of the amino acid neurotransmitters in the striatum focal cerebral ischemia in rat and the effect of Acorus tatarinowii Schott, one of inducing resuscitation drugs, for 4 of amino acid neurotransmitters.

METHODSTwenty four rats were divided into four groups (n = 6): control group, cerebral ischemia group, sham operation group and Acorns tatarinowii Schott treated group. Rats were established into models of cerebral ischemia by occluding bilateral thread cork method. Formation sampling were performed in a striatum area using microdialysis and the detection of biological sample including aspartic acid, glutamic acid, glycine and gamma-aminobutyric acid by high performance liquid chromatography (HPLC) electrochemical detector system.

RESULTSCompared with the control, the all contents of 4 kinds of the amino acids were significantly increased during cerebral ischemia (P < 0.01). Compared with the cerebral ischemia group, the contents of aspartic acid, glutamic acid that were excitatory amino acids were remarkably decreased in the striatum for Acorus tatarinowii Schott treated group (P < 0.01), It was no significant influence on gamma-aminobutyric acid and glycine that belonged to inhibitory amino acid in a nascent condition but with a elevating in the later period of microdialysis.

CONCLUSIONAcorus tatarinowii Schott can enter the cerebral parenchyma through blood brain barrier and cut down glutamic acid,aspartic acid increased during cerebral ischemia. As a result, the neurotoxicity attributed to the excitatory amino acid has been released in excessive amounts declined so as to avoid the secondary impairment of neurons caused by excitatory amino acids pernicious effects after ischemia. It may be one of the protective mechanism of drugs for inducing resuscitation resembling EAA receptor antagonists to ischemi brain.

Acorus ; chemistry ; Animals ; Brain Ischemia ; metabolism ; Corpus Striatum ; metabolism ; Disease Models, Animal ; Excitatory Amino Acids ; metabolism ; Male ; Neurotransmitter Agents ; metabolism ; Rats ; Rats, Sprague-Dawley

Periventricular white matter damage is one of the characteristics of brain damage in preterm infants, and it is the most important type of encephalopathy. The pathological changes including the white matter of coagulation necrosis, oligodendrocyte damage, myelin damage, axonal injury and reactive gliosis and microglia infiltration in necrotic areas. All of these lesions are closely related to the nervous system sequelae in later-neonatal period. The pathogenesis of periventricular leukomalacia in premature infants are mainly cause by its immature brain vascular, and precursor oligodendrocytes of the attack of hypoxia, ischemia, infection, oxygen free radicals, inflammatory cytokines, increasing glutamate, and other high-risk factors. In this paper, an overview of progress in the study of the pathogenesis of periventricular white matter damage in premature infants through literature review to provide a theoretical support for clinical prevention, diagnosis and treatment.
Apoptosis ; Cerebrovascular Circulation ; Cytokines ; physiology ; Excitatory Amino Acids ; toxicity ; Humans ; Infant, Newborn ; Infant, Premature ; Leukomalacia, Periventricular ; classification ; etiology ; Risk Factors

OBJECTIVETo study the effect of 3'-methoxy puerarin on cerebral ischemic glutamic acid, aspartic acid, taurine and gamma-aminobutyric acid inhibitory of rats and investigate the protective mechanisms of cerebral ischemia-reperfusion.

METHODUsing middle cerebral artery occlusion rat model, to collect extracellular fluid in rat striatal amino acid neurotransmitters by brain microdialysis and HPLC techniques with fluorescence detection before and after 3'-methoxy puerarin treatment four kinds of amino acids changes.

RESULT3'-methoxy puerarin reduced concentrations of excitatory amino acid (EAA) Asp and Glu, while Tau and GABA inhibitory amino acids were significantly reduced.

CONCLUSION3'-methoxy puerarin reduce ischemia-induced brain EAA toxicity against EAA neurotoxicity, regulate the brain neurotransmitter amino acid content, improve the excitatory and inhibitory amino acid balance is one of the mechanisms that to improve and protect the important acute cerebral infarction in rat brain nuclei.

Animals ; Brain Ischemia ; drug therapy ; metabolism ; Excitatory Amino Acids ; metabolism ; Female ; Isoflavones ; therapeutic use ; Male ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; drug therapy ; metabolism

OBJECTIVETo study the involvement of excitatory amino acid system in astrocytes activation caused by dimethoate.

METHODSPure-cultured astrocytes were gained by three passages from primary cultured rat nerve cells, then treated with 10(-6),10(-5),10(-4) mol/L dimethoate for 48 h, 50 micromol/L and 100 micromol/L MK801, a NMDA receptor blocker, was used to intervene the effects induced by 10(-4) mol/L dimethoate. HPLC-FLD was utilized to measure the concentrations of excitatory amino acid (EAA), RT-PCR was used to detect the expression levels of NR2B, GLT-1, GLAST, GFAP and S100beta mRNA, and immunofluorescence staining method was applied to measure the expression levels of GFAP and S100beta proteins.

RESULTSThe expression levels of GLAST mRNA in all exposure groups were 67.8%, 68.6% and 76.2% of control level, respectively, which were significantly lower than that of control group (P < 0.05); The concentrations of EAA significantly decreased in 10(-4) mol/L dimethoate group, as compared with control group (P < 0.01); the expression levels of GFAP mRNA in 10(-4) mol/L dimethoate group, of S100beta mRNA in 10(-5) mol/L dimethoate group, of GFAP protein in 10(-4) mol/L and 10(-5) mol/L dimethoate groups and S100beta protein in 10(-4) mol/L dimethoate group were significantly higher than those in control group (P < 0.01). The expression levels of GLT-1 and GLAST mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01), the expression levels of NR2B mRNA in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups increased significantly, as compared with control group (P < 0.05 or P < 0.01); the concentration of Glu in 10(-4) mol/L dimethoate plus 100 micromol/L MK801 group increased significantly, as compared with 10(-4) mol/L dimethoate group (P < 0.01); the expression levels of GFAP mRNA and protein in 10(-4) mol/L dimethoate plus 50 micromol/L or 100 micromol/L MK801 groups decreased significantly (P < 0.01); S100beta protein expression level in 50 micromol/L MK801 intervention group was significantly higher than thatl in control group (P < 0.01).

CONCLUSIONExcitatory amino acid system involved in astrocytes activation caused by dimethoate. MK801 was useful to control astrocytes gliosis.

Animals ; Astrocytes ; drug effects ; metabolism ; Cells, Cultured ; Dimethoate ; toxicity ; Dizocilpine Maleate ; pharmacology ; Excitatory Amino Acids ; metabolism ; Rats ; Receptors, N-Methyl-D-Aspartate ; antagonists & inhibitors

OBJECTIVE: Excitatory amino acids play important roles in the development of secondary pathology following spinal cord injury (SCI). This study was designed to evaluate morphological changes in the dorsal horn of the spinal cord and assess profiles of pain behaviors following intraspinal injection of N-methyl-D-aspartate (NMDA) or quisqualate (QUIS) in rats. METHODS: Forty male Sprague-Dawley rats were randomized into three groups : a sham, and two experimental groups receiving injections of 125 mM NMDA or QUIS into their spinal dorsal horn. Following injection, hypersensitivity to cold and mechanical stimuli, and excessive grooming behaviors were assessed serially for four weeks. At the end of survival periods, morphological changes in the spinal cord were evaluated. RESULTS: Cold allodynia was developed in both the NMDA and QUIS groups, which was significantly higher in the QUIS group than in the NMDA group. The mechanical threshold for the ipsilateral hind paw in both QUIS and NMDA groups was significantly lower than that in the control group. The number of groomers was significantly higher in the NMDA group than in the QUIS group. The size of the neck region of the spinal dorsal horn, but not the superficial layer, was significantly smaller in the NMDA and QUIS groups than in the control group. CONCLUSION: Intraspinal injection of NMDA or QUIS can be used as an excitotoxic model of SCI for further research on spinal neuropathic pain.
Animals ; Cold Temperature ; Excitatory Amino Acids ; Grooming ; Horns ; Humans ; Hyperalgesia ; Hypersensitivity ; Injections, Spinal ; Male ; N-Methylaspartate ; Neck ; Neuralgia ; Quisqualic Acid ; Rats ; Rats, Sprague-Dawley ; Salicylamides ; Spinal Cord ; Spinal Cord Injuries

OBJECTIVETo observe the effects of polydatin on dynamic changes of excitatory amino acids in cerebrospinal fluid and water content of brain tissue of cerebral hemorrhage rats. And to discuss the therapeutic action and mechanisms of polydatin on brain hemorrhagic injured rats.

METHODA quantitative determination method of Asp and Glu was established by microdialysis-HPLC. The cerebral hemorrhage model in rats was induced by local injection of type VII collagenase. The dynamic changes of Asp and Glu in cerebrospinal fluid were observed on 0, 6, 12, 24, 36, 48, 60, 72, 84, 96, 108 h of cerebral hemorrhage rats, and then the water content of brain tissue was detected.

RESULTThe content of Asp and Glu increased rapidly within 24 h after cerebral hemorrhage, and to the highest in 24 h, then decreased gradually. Compared with the cerebral hemorrhage model group, the content of Asp and Glu increased slowly in polydatin group, and there were significant differences in 12-72 h and 6-84 h (P < 0.01, P < 0.05), but there was no significant difference after 84 h and 96 h. Compared with sham group, water content of brain tissue significantly higher in model group, while significantly lower (P < 0.01) in polydatin group.

CONCLUSIONPolydatin can inhibit increasing content of Asp and Glu in cerebrospinal fluid dynamics, and significantly inhibit cerebral edema of cerebral hemorrhage rats. It shows that the mechanisms of anti-cerebral hemorrhage injury of polydatin may be related to increasing of excitatory amino acids after cerebral hemorrhage.

Animals ; Aspartic Acid ; cerebrospinal fluid ; Cerebral Hemorrhage ; cerebrospinal fluid ; drug therapy ; Disease Models, Animal ; Drugs, Chinese Herbal ; therapeutic use ; Excitatory Amino Acids ; cerebrospinal fluid ; Glucosides ; therapeutic use ; Glutamic Acid ; cerebrospinal fluid ; Humans ; Male ; Rats ; Rats, Sprague-Dawley ; Stilbenes ; therapeutic use

OBJECTIVETo investigate the effect and mechanisms of dimethoate on the primary cultured cortical neuronal cell injury.

METHODSCortical neuronal cells were isolated and cultured in serum free medium for 6 days in vitro, and 1, 5, 10, 50 and 100 micromol/L dimethoate were added to the medium and intracellular SOD, MDA and GSH. The content of excitatory amino acid was measured after 48 hours. Flow cytometry was used to detect the neuronal cell apoptosis.

RESULTSAfter 48 h, the activity of SOD and the content of GSH decreased [(1.04 +/- 0.02), (0.99 +/- 0.02), (0.96 +/- 0.02), (0.91 +/- 0.02) U/mg pro] [(219.35 +/- 6.79), (205.6 +/- 6.29), (194.06 +/- 2.63), (93.68 +/- 7.56) mg/g pro], and the content of MDA increased obviously with 5, 10, 50 and 100 micromol/L dimethoate [(21.22 +/- 0.29), (24.01 +/- 0.34), (27.15 +/- 1.02), (32.91 +/- 1.39) nmol/mg pro]; The content of Asp from 10 to 100 micromol/L dose group was higher than the control group and the content of Glu from 1 to 100 micromol/L dose group was higher than the control group. The apoptosis rate had great significance between 1 to 100 micromol/L dose groups and control group. When treated with dimethoate, MDA content in neuron was positively correlated with the content of EAAs with the increase of dimethoate. The correlative coefficient was 0.937 and 0.759 respectively (P < 0.01), while it was negatively correlated with the content of GSH. The correlative coefficient was -0.868 and -0.801 respectively (P < 0.01).

CONCLUSIONThe oxidative damage and changes of excitatory amino acid content induced by Dimethoate contribute to the primary cultured rat cortical neuron apoptosis.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Cells, Cultured ; Cerebral Cortex ; cytology ; Dimethoate ; toxicity ; Excitatory Amino Acids ; metabolism ; Glutathione ; metabolism ; Malondialdehyde ; metabolism ; Neurons ; drug effects ; metabolism ; pathology ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism

During operations, neurosurgeons usually perform multiple temporary occlusions of parental artery, possibly resulting in the neuronal damage. It is generally thought that neuronal damage by cerebral ischemia is associated with extracellular concentrations of the excitatory amino acids. In this study, we measured the dynamics of extracellular glutamate release in 11 vessel occlusion (VO) model to compare between single occlusion and repeated transient occlusions within short interval. Changes in cerebral blood flow were monitored by laser-Doppler flowmetry simultaneously with cortical glutamate level measured by amperometric biosensor. From real time monitoring of glutamate release in 11 VO model, the change of extracellular glutamate level in repeated transient occlusion group was smaller than that of single occlusion group, and the onset time of glutamate release in the second ischemic episode of repeated occlusion group was delayed compared to the first ischemic episode which was similar to that of single 10 min ischemic episode. These results suggested that repeated transient occlusion induces less glutamate release from neuronal cell than single occlusion, and the delayed onset time of glutamate release is attributed to endogeneous protective mechanism of ischemic tolerance.
Arteries ; Biosensing Techniques ; Brain Ischemia ; Excitatory Amino Acids ; Glutamic Acid ; Glycosaminoglycans ; Humans ; Ischemia ; Laser-Doppler Flowmetry ; Neurons ; Parents

Animals ; Brain ; metabolism ; Brain Ischemia ; metabolism ; Excitatory Amino Acids ; metabolism ; Female ; Male ; Panax ; chemistry ; Random Allocation ; Rats ; Rats, Wistar ; Reperfusion Injury ; prevention & control ; Saponins ; isolation & purification ; pharmacology